window.addEventListener('load', function() {
  var hour = document.querySelector('.hour');
  var minute = document.querySelector('.minute');
  var second = document.querySelector('.second'); 
  var inputTime = +new Date('2022-11-29 00:00:00'); 
  countDown();
  setInterval(countDown, 1000);

  function countDown() {
    var nowTime = +new Date(); 
    var times = (inputTime - nowTime) / 1000;
    var h = parseInt(times / 60 / 60 % 24); 
    h = h < 10 ? '0' + h : h;
    hour.innerHTML = h; 
    var m = parseInt(times / 60 % 60);
    m = m < 10 ? '0' + m : m;
    minute.innerHTML = m;
    var s = parseInt(times % 60); 
    s = s < 10 ? '0' + s : s;
    second.innerHTML = s;
  }
})